Exploring Life's Building Blocks: Parts of a Cell and Defining Life

1. Parts of a Cell

2. How do we know if something is alive? How do we define what it means to be alive?

3. Defining Life There is no universal definition of life. To define life in terms is still a challenge for scientists. Conventional definition: must exhibit the following criteria: • Homeostasis: Regulation of the internal environment to maintain a constant state; for example, sweating to reduce temperature. • Organization: Being composed of one or more cells, which are the basic units of life. • Metabolism: Consumption of energy • Growth: A growing organism increases in size in all of its parts, rather than simply accumulating matter. • Adaptation: The ability to change over a period of time in response to the environment • Response to stimuli: A response can take many forms, from the contraction of a unicellular organism when touched to complex reactions involving all the senses of higher animals. A response is often expressed by motion, for example, the leaves of a plant turning toward the sun or an animal chasing its prey. • Reproduction: The ability to produce new organisms.

4. Cell Theory - Review • All living things are made of cells • Cells are the basic units of structure (form) and function (purpose) in living things. • Living cells come only from other living cells Brainpop: Cells

5. What technology was created that allowed cells to be discovered? • Hint: you could not SEE a cell without this piece of equipment. • Another hint: we used this piece of equipment during our last unit of study.

6. What are cells? • Cells are the basic unit of structure and function in living things. • All living things are made up of cells • Cell are the building blocks of life • Cells are specialized to do certain jobs in different regions of your body. • There are about 200 different types of cells in your body. • Cells are so tiny you could fit more than a million of them on a period at the end of a sentence.

7. Cells • Cells were named by Robert Hooke. • 1st scientist to call spaces in cork cells he observed under the microscope “cells.” • Comes from the Latin word cella which means “little rooms”. • Unicellular: one cell – bacteria. • Multicellular: many cells –humans have over 200 different types of cells (blood, bone, skin) and an estimated 100 trillion total cells.

8. Cells • Each cell is an amazing world unto itself: it can take in nutrients, convert these nutrients into energy, carry out specialized functions, and reproduce as necessary. • Each cell stores its own set of instructions for carrying out each of these activities. • Organelles: small structures, or “organs” within cells that perform a specific function

9. PLANT AND ANIMAL CELLS

10. Cell Theory: • All organisms are made up of one or more cells. • The cell is the basic unit of organization of all organisms. • All cells come from other cells already in existence.

11. CELL WALL: PLANT • Function:Gives the cell most of its support and structure • A thick, rigid membrane that surrounds a plant cell • Bonds with other cell walls to form the structure of the plant

12. Plant Cell Cell Wall

13. CELL MEMBRANEPlant and Animal • Function:Semi permeable, allowing some substances to pass into the cell and blocking others. • Thin layer of protein and fat that surrounds the cell

14. Animal Cell Cell Membrane

15. Plant Cell Cell Membrane

16. Cytoplasm • Function:Where the organelles are located. • The jellylike material located inside the cell. • In Both Plant and Animal Cell

17. Animal Cell Cytoplasm

18. Plant Cell Cytoplasm

19. ENDOPLASMIC RETICULUM • Function:transports materials through the cell • Rough ER is covered with ribosome's that give it a rough appearance • In both Plant and Animal Cell

20. Animal Cell Smooth ER Rough Endoplasmic Reticulum

21. Plant Cell Smooth ER Rough Endoplasmic Reticulum

22. Chloroplast • Function: Manufactures food through photosynthesis. Uses energy from sunlight to make sugar. • An elongated or disc-shaped organelle containing chlorophyll • Only in Plant Cell

23. Plant Cell Chloroplast

24. Golgi Bodies • Function:Golgi bodies are the packaging and secreting organelles of the cell. • Are stacks of membrane-covered sacs that package and move proteins to the outside of the cell. • In Both Plant and Animal Cell

25. Animal Cell Golgi Body

26. Plant Cell Golgi Body

27. Lysosome • Function:Where the digestion of cell nutrients takes place • Also called cell vesicles • Spherical organelles surrounded by a membrane • They contain digestive enzymes • In Both Plant and Animal Cell

28. Animal Cell Lysosome

29. Plant Cell Lysosome

30. Mitochondria • Functions:Where energy is released. • Rod-shaped organelles with a double membrane • Membrane is infolded many times, forming a series of projections (called cristae) • In Both Plant and Animal Cell

31. Animal Cell Mitochondria

32. Plant Cell Mitochondria

33. Nucleus:The Manager • Function:Controls many of the functions of the cell • Spherical body containing many organelles, including the nucleolus • Contains DNA (in chromosomes) • Surrounded by the nuclear membrane • In Both Plant and Animal Cell

34. Nucleus Animal Cell

35. Plant Cell Nucleus

36. Ribosomes • Function:Small structures in the cytoplasm that create proteins. • Ribosome's are either free floating in the cytoplasm of a cell or attached to endoplasmic reticulum in a cell. • In both Plant and Animal Cell

37. Animal Cell Ribosomes

38. Plant Cell Ribosomes

39. Vacuole • Function:Like your suitcase, a vacuole is a temporary storage space for the cell. • Fluid-filled, membrane-surrounded cavities inside a cell • Filled with food being digested and waste material that is on its way out of the cell • Many in Animal, One large in Plant

40. Animal Cell Vacuole

41. Plant Cell Vacuole

42. Nuclear Membrane • Protects and guards the nucleus • Controls movement of materials in and out of the nucleus • Keeps the DNA inside the nucleus • Allows other materials to pass in and out of the nucleus • In Both Plant and Animal Cell

43. Animal Cell Nuclear Membrane

44. Nuclear Membrane Plant Cell

45. Nucleolus • Controls the cells activity… The Brain • Inside the nucleus • The nucleolus is the part of the nucleus which contains most of the genes that code for the synthesis of ribosomal RNA • In both Plant and Animal Cell

46. Nucleolus Animal Cell

47. Nucleolus Plant Cell

48. Chromosomes • Contains the DNA • Located in the nucleus • In Both Plant and Animal Cell

49. Animal Cell Chromosomes

50. Plant Cell Chromosomes